Ummm...well, I hear mixed things about JVC, some people think they're a great bargain/quality brand, other people think they're garbage, just depends on the experience the user had. I'll tell you this, making "claims" and actually backing those claims up are two different things, especially in an unregulated industry.
You can read the reviews, I'm sure you have read some, but usually people don't know what they're talking about in the "public" reviews anyway. Search on some car audio forums for some reviews (if you can find 'em:
www.elitecaraudio.com,
www.sounddomain.com,
www.carstereo.com, etc...) and see what some people who are "into" audio say, and not just your "I needed a new cd player and this one had a TV in it" consumer. Outside of that, I don't have a whole lot of experience with JVC, so I can't help you more.
Oh, and Bose...

Don't like 'em. Over priced for what it is.